Window frames with molded plastic corners and lineal rail sections that may be cut to a desired length and joined between corners to produce a frame are commercially available. None, however, includes a means for aligning corners with the straight sections or for connecting them so that the frame can be assembled around the glass or plastic glazing. Prior structures that designers may purport to guide or otherwise locate the lineal section with its corner mandate use of complicated dies, which increases cost of manufacture. The frame is also made heavy as a result because more thermoplastic is used to form the correspondingly complex hollow extrusions. In mobile home and RV applications, however, it's desirable that weight be minimized for efficient travel.
None of the molded corners or lineal sections heretofore available provides integrally formed seals that may be extruded/molded concurrently with the frame sections. Intuitively, this would offer never before seen advantages such as eliminating labor intensive steps like caulking and installing seals necessary for ensuring a watertight fit around the frame and glazing. Additionally, the abutting surfaces where the corners and rails meet on prior thermoplastic window frames have no seal and thus must likewise be caulked and/or treated. Points where lineal sections and corners meet, therefore, typically appear sloppy and unclean as a result. Prior frames in which corners may be molded and joined to straight lineal pieces require additional steps to manufacture, which amounts to additional capital expenditure and lead time. The production and maintenance of such frames and windows are expensive and time consuming. These problems are multiplied when sliding windows are incorporated into such frames.
Thus, there is a need for a new plastic window frame that may be assembled in a time-efficient and cost-efficient manner, such that the frame can be assembled around the glass without adding seals or caulking thereby lowering the overall costs of window assembly. The present invention meets this need.